使用客户端库时进行身份验证

本页面介绍了如何使用客户端库和应用默认凭据访问 Google API。

通过客户端库，您可以更轻松地使用支持的语言访问 Google Cloud API。您可以直接通过向服务器发出原始请求来使用 Google Cloud API，但客户端库可提供简化，从而显著减少您需要编写的代码量。这对于身份验证尤其如此，因为客户端库支持应用默认凭据 (ADC)。

如果您想使用 API 密钥，请不要使用 ADC。如需了解详情，请参阅将 API 密钥与客户端库搭配使用。

将应用默认凭据与客户端库搭配使用

如需使用应用默认凭据对应用进行身份验证，您必须先为应用运行的环境设置 ADC。使用客户端库创建客户端时，客户端库会自动检查和使用您提供给 ADC 的凭据，从而向代码使用的 API 进行身份验证。您的应用无需明确对令牌进行身份验证或管理；这些要求由身份验证库自动管理。

对于本地开发环境，您可以使用 gcloud CLI 使用用户凭据设置 ADC。对于生产环境，您可以通过关联服务账号来设置 ADC。

示例客户端创建

以下代码示例为 Cloud Storage 服务创建客户端。您的代码可能需要不同的客户端；这些示例仅用于展示如何在无需任何代码来明确进行身份验证的情况下创建客户端并使用它。

您必须先为您的环境设置 ADC 并安装 Cloud Storage 客户端库，然后才能运行以下示例。

Go

import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/storage"
	"google.golang.org/api/iterator"
)

// authenticateImplicitWithAdc uses Application Default Credentials
// to automatically find credentials and authenticate.
func authenticateImplicitWithAdc(w io.Writer, projectId string) error {
	// projectId := "your_project_id"

	ctx := context.Background()

	// NOTE: Replace the client created below with the client required for your application.
	// Note that the credentials are not specified when constructing the client.
	// The client library finds your credentials using ADC.
	client, err := storage.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("NewClient: %w", err)
	}
	defer client.Close()

	it := client.Buckets(ctx, projectId)
	for {
		bucketAttrs, err := it.Next()
		if err == iterator.Done {
			break
		}
		if err != nil {
			return err
		}
		fmt.Fprintf(w, "Bucket: %v\n", bucketAttrs.Name)
	}

	fmt.Fprintf(w, "Listed all storage buckets.\n")

	return nil
}

Java

import com.google.api.gax.paging.Page;
import com.google.cloud.storage.Bucket;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
import java.io.IOException;

public class AuthenticateImplicitWithAdc {

  public static void main(String[] args) throws IOException {
    // TODO(Developer):
    //  1. Before running this sample,
    //  set up Application Default Credentials as described in
    //  https://cloud.google.com/docs/authentication/external/set-up-adc
    //  2. Replace the project variable below.
    //  3. Make sure you have the necessary permission to list storage buckets
    //  "storage.buckets.list"
    String projectId = "your-google-cloud-project-id";
    authenticateImplicitWithAdc(projectId);
  }

  // When interacting with Google Cloud Client libraries, the library can auto-detect the
  // credentials to use.
  public static void authenticateImplicitWithAdc(String project) throws IOException {

    // *NOTE*: Replace the client created below with the client required for your application.
    // Note that the credentials are not specified when constructing the client.
    // Hence, the client library will look for credentials using ADC.
    //
    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests.
    Storage storage = StorageOptions.newBuilder().setProjectId(project).build().getService();

    System.out.println("Buckets:");
    Page<Bucket> buckets = storage.list();
    for (Bucket bucket : buckets.iterateAll()) {
      System.out.println(bucket.toString());
    }
    System.out.println("Listed all storage buckets.");
  }
}

Node.js

/**
 * TODO(developer):
 *  1. Uncomment and replace these variables before running the sample.
 *  2. Set up ADC as described in https://cloud.google.com/docs/authentication/external/set-up-adc
 *  3. Make sure you have the necessary permission to list storage buckets "storage.buckets.list"
 *    (https://cloud.google.com/storage/docs/access-control/iam-permissions#bucket_permissions)
 */
// const projectId = 'YOUR_PROJECT_ID';

const {Storage} = require('@google-cloud/storage');

async function authenticateImplicitWithAdc() {
  // This snippet demonstrates how to list buckets.
  // NOTE: Replace the client created below with the client required for your application.
  // Note that the credentials are not specified when constructing the client.
  // The client library finds your credentials using ADC.
  const storage = new Storage({
    projectId,
  });
  const [buckets] = await storage.getBuckets();
  console.log('Buckets:');

  for (const bucket of buckets) {
    console.log(`- ${bucket.name}`);
  }

  console.log('Listed all storage buckets.');
}

authenticateImplicitWithAdc();

PHP

// Imports the Cloud Storage client library.
use Google\Cloud\Storage\StorageClient;

/**
 * Authenticate to a cloud client library using a service account implicitly.
 *
 * @param string $projectId The Google project ID.
 */
function auth_cloud_implicit($projectId)
{
    $config = [
        'projectId' => $projectId,
    ];

    # If you don't specify credentials when constructing the client, the
    # client library will look for credentials in the environment.
    $storage = new StorageClient($config);

    # Make an authenticated API request (listing storage buckets)
    foreach ($storage->buckets() as $bucket) {
        printf('Bucket: %s' . PHP_EOL, $bucket->name());
    }
}

Python

from google.cloud import storage

def authenticate_implicit_with_adc(project_id="your-google-cloud-project-id"):
    """
    When interacting with Google Cloud Client libraries, the library can auto-detect the
    credentials to use.

    // TODO(Developer):
    //  1. Before running this sample,
    //  set up ADC as described in https://cloud.google.com/docs/authentication/external/set-up-adc
    //  2. Replace the project variable.
    //  3. Make sure that the user account or service account that you are using
    //  has the required permissions. For this sample, you must have "storage.buckets.list".
    Args:
        project_id: The project id of your Google Cloud project.
    """

    # This snippet demonstrates how to list buckets.
    # *NOTE*: Replace the client created below with the client required for your application.
    # Note that the credentials are not specified when constructing the client.
    # Hence, the client library will look for credentials using ADC.
    storage_client = storage.Client(project=project_id)
    buckets = storage_client.list_buckets()
    print("Buckets:")
    for bucket in buckets:
        print(bucket.name)
    print("Listed all storage buckets.")

Ruby

def authenticate_implicit_with_adc project_id:
  # The ID of your Google Cloud project
  # project_id = "your-google-cloud-project-id"

  ###
  # When interacting with Google Cloud Client libraries, the library can auto-detect the
  # credentials to use.
  # TODO(Developer):
  #   1. Before running this sample,
  #      set up ADC as described in https://cloud.google.com/docs/authentication/external/set-up-adc
  #   2. Replace the project variable.
  #   3. Make sure that the user account or service account that you are using
  #      has the required permissions. For this sample, you must have "storage.buckets.list".
  ###

  require "google/cloud/storage"

  # This sample demonstrates how to list buckets.
  # *NOTE*: Replace the client created below with the client required for your application.
  # Note that the credentials are not specified when constructing the client.
  # Hence, the client library will look for credentials using ADC.
  storage = Google::Cloud::Storage.new project_id: project_id
  buckets = storage.buckets
  puts "Buckets: "
  buckets.each do |bucket|
    puts bucket.name
  end
  puts "Plaintext: Listed all storage buckets."
end

后续步骤

• 详细了解应用默认凭据。
• 大致了解在 Google 进行身份验证。
• 查看身份验证使用场景。